Hydraulic hoisting and rotating apparatus



Aug. 18, 1942. v 2,293,088 A HYDRAULIC HOISTING AND ROTATING APPARATUS Original Filed March 7,- 1938 INVENTOR Maew/FWcKEz's ATTO Patented Aug. 18, 1942 nrnmumc nors'rmc AND aora'rmc arraaarus Harry F. Vickera, Detroit, Mich, assignor to Vickers, Incorporated, Detroit, Mich, a corporation of Michigan Original application March 7, 1938, Serial No.

194,284. Divided and this applicationseptemher 4,- 1941, Serial No. 409,461

8 Claims.

This'invention relates to power transmissions and more particularly to those of the fluid type wherein a power transmitting fluid, such as oil,

and hereinafter referred to as such, is utilized for the transmission of power between one or more pumps and one or more fluid motors. mounted in an oil reservoir i6 and has a drive This application is a division of a co-pending shaft I 8 driven from an electric motor 20 by application Serial No. 194,284, filed March 7, suitable drive means, such as the belt 22. The 1938. displacement of the pump l4 may be varied by It is an object of the present invention to promeans of a swinging yoke 24 pivoted at 26. In vide a power transmission system for operating the position shown, the displacement of the pump a translatable and rotatable load device,'and is zero while, if the yoke 24 be swung downwhich may be constructed as a compact unitary wardly, the displacement of the pump is inpower device providing for smooth, yet rapid, creased in proportion to the amount by which translatory movement of the load device under the yoke is swung. manual control and which also provides for ac- Suitable regulating means such as the cylinder curate follow-up operation of the load device to 28 are provided for controlling the position of any angular position desired. 7 the yoke 24. The cylinder 28 contains a. freely A further object is to provide a system of this slidable piston '30, the stem 32 of which is concharacter in which the rotation of the load denected by a link 34 to the yoke 24. A spring 36 vice can be afiected only when the load device normally biases the piston 88 to its lowermost has been translated to one certain position and position, that is, the position of maximum distoprovide reliable, safe, and trouble-proof interplacement. For the purpose of reducing the locking means for insuring this result. pump displacement as may be required to main- A further feature of the invention resides in tain a constant delivery pressure at the pump, the provision of novel limit stop means for pre--' the annular chamber 38 of the cylinder.'28 conventing continued rotation of the load device benects-with a conduit 48 which is connected in the yond a predetermined point by disabling the hycircuits as will be described hereinafter. The exdraulic. drive mechanism and which does not, treme ends of the cylinder 28 are connected to however, prevent operationof the drive mechathe tank by a conduit 42.

nism in the reverse direction to back the load.-

device away from its stop. a

A further object is to provide positive and re-. liable latch means for releasablyrestraining the load device in one position of its translatory movement together with safety interlocking means for releasing the'latch means and preventing translation of load device until the latch means is fully released. I

Further objects have to do with detailed constructional features and coordinated operation of parts as more fully set forth in the specification and claims.

The single figure is a diagrammatic view of a hydraulic system embodyinga-preferred form of the present invention.

The embodiment of the invention selected for illustration is. suitable for operating a vertically translatable head III in such a manner that the head may be either retained'in its upper and inoperative position, as illustrated, or may be moved downwardly in its lowermost position. In this I latter position a rotatable member 12, which is desired angular position by means of suitable follow-up control mechanism.

The power transmission system for accomplishing these movements comprises a pump i4, preferably of the variable displacement type which is 4 The pump l4 withdraws oil from the tank through a conduit 43 and delivers oil through a delivery conduit 44, having acheck valve 45 for preventing return flow to the pump. The conduit 44 extends to a chamber 46 formed in a control block 48. The chamber 45 constitutes -.:.the maimpressure chamber of a pilot operated balanced relief valve 50 which is of the same general construction as the valve disclosed in my Patent No. 2,043,453 of June 9, 1936, and is adapted to by-pass oil to a chamber 52 whenever the -oil in the control chamber 54 is vented to tank at a faster rate than it can enter the chamber 54 through the restricted orifice 56. A pilot relief valve 58 serves to thus vent the chamber 54 to the chamber 52 through the central bore 60 whenever the pressure in chamber 54 exceeds a predetermined safe value. A branch conduit 62 also communicates with the chamber 54 for the purpose of venting the same under certain conditions, to be later described. 4 v

'The chamber 52 connects by a conduit 64 with the tank IS. A conduit 56 in the valve block 58 communicates between the pressure chamber 45 I .carried by the head it, may be rotated to any and the pressure port of a four-way reverse valve ing provided for releasably restraining valve in either position without requiring continued enrgization of either solenoid. The cylinder ports of the valve 68 connect by conduits 82 and 84 with the rod and head ends of a pair of reciprocating fluid motors 86 and 88.

These motors may comprise a pair of stationary cylinders 90 and 92 in which are freely slidable a pair of differential pistons 94 and 96, having rods 98 and I00, upon which the head I is supported and secured. The conduit 40 connects to the cylinder 90 at a point just below the piston 94 in its uppermost position. The pistons 94 and 96 are formed with tapered ends, as illustrated, and the conduits leading to the ends of the cylinders are provided with check valve controlled, restricted branches, as shown, for providing a hydraulically cushioned deceleration of the pistons at either end of the stroke in the well-known manner. The rods 98 and I00 are provided with collar-like portions I02 and I04 which may be engaged by a plurality of latch means, four of which are illustrated.

The latch means may comprise cylindrical plungers I06, having their inner ends beveled, as shown, and normally biased inwardly by springs I08. Each of the plungers I06 is formed to act as athree-way valve which connects with the spring chambers when the latches are in their inward position, illustrated. When the latches are retracted outwardly, these valves are connected in a series ircuit starting at the conduit IIO which is in communication with the conduit 82 at all times. A series of conduits H2, H4, H6 and H8 completes this series circuit and terminates at the operating chamber .I of a pilot operated three-way valve I22.

The valve I22 has an operating chamber I23 at its lower end containing a spring I24. The chamber I23 connects by a conduit I25 to the lower cylinder port of valve 68. The valve I22 may be provided with a suitable spring detent means I26. =A conduit I28 connects to' -the conduit 84 at a point beyond a check valve I30 and is adapted to be selectively connected by the valve I22 with either, a conduit I32 having a check valve I34 therein and communicating with the conduit 82, or a conduit I36 communieating with the lower tank port of the four way valve 68. The conduit I36 may have a restricted portion I38 therein.

Communicating with the conduit 44 is a branch conduit I40 which connects to a two-way valve I42. The latter has an upwardly projecting stem I44 which may be depressed by an arm I46, carried by the head I0 when the latter descends to its lowermost position. When the valve plunger I44 is depressed, communication is established from conduit I40 to a conduit I48, leading to the pressure port of a rotary follow-up valve I50. The valve I50, which is indicated only diagrammatically in the drawing, may be of any suitable construction whereby pressure and tank connections may be selectively reversed or shut off in accordance with the difference in angular position between .a rotary input member and a rotary follow-back or response member. One example of a valve of this character is illustrated in my Patent No. 2,030,902 of February 18,1936. The tank port of the valve I50 may be connected to tank by a conduit I52 while the controlled ports are connected by conduits I54 and I56 with a rotary fluid motor I58. The latter may be of similar construction to the pump 24, except that the yoke of the motor is maintained at a fixed, though preferably adjustable, angle, at all times.

The rotary input element of the valve I50 may be connected by means, not illustrated, with a sleeveI60 which is connected by bevel gearing I62 to a handwheel I64. The follow back or response element of the valve I50 may be connected with a shaft I 66, on which the sleeve I 60 is rotatably mounted. Preferably stop means I68 for limiting the relative angular displacement between sleeve I60 and shaft I66 are provided to prevent displacement of the two rotary valve controlling elements beyond the amount necessary to fully open the valve in either direction. strong so as to provide a mechanical drive from the handwheel .I64 to the shaft I66, should the motor I 58 for any reason fail to respcnd to the operation of the follow-up valve I50.

The motor. I58 has an output shaft I'I0 connected by a gear I'I2 with a gear I" mounted for rotation in a fixed bearing, not illustrated. The gear I'I4 has an internally splined hub in which a splined shaft "6 may be slidably but non-rotatably mounted. The shaft H6 is retatably mounted in the head I0 and connects by gearing I18 to the rotatable member I 2. The gear "2 at the motor I58 also connects by gearing I with the response shaft I66.

For the purpose of limiting the angular rotation of the rotary member I2, the gear "4 carries a gear I82 meshing with a gear I 84 which connects by bevel gearing and shaft I86 to a rotatable limit stop arm I88, mounted forrotation adjacent the valve block 48. The gear ratios are such that one revolution of the member I88 corresponds to the desired range of angular rotation of the member I2. The member I88 is adapted to contact a lever I90 which is connected to operate a rotary pilot valve I92 which is normally spring centered in the position illustrated, but which may be deflected clockwise or counterclockwise by operation of the lever I88. The. valve I92 has one port I94 connected to the conduit 62. Ports I96 and I98 are adapted to be selectively connected with the port I94 by clockwise and counter-clockwise rotation respectively of the valve I92. Port 200 is connected to the tank port of valve 68 by a conduit 202 and serves merely to drain any seepage of fluid from the valve I92. The ports I96 and I98 connect by conduits 204 and 206 to the controlled ports of follow-up valve I50, suitable check valves 208 and 2I0 being provided in these conduits.

Suitable drain conduits 203, 205, 201, 209 connect the spring chambers behind the latch plungers I 06 with the .tank chamber 52 in block 48. A branch 2 also connects to the lower end of valve I42.-

The input sleeve I60 for the follow-up valve may be remotely operated by a suitable selsyn transmission system comprising a motor 2I2 geared to the sleeve I60 and the generator 2l4 geared to the remote handwheel 2I6. A flywheel 2I8 may be provided at the handwheel 2 I6 to limit the acceleration which may be imparted thereto. Preferably a bearing repeater is also provided at the remote control station, comprising a Selsyn generator 220 geared to the rotary This means may be made suffiiciently member I2 and a Selsyn motor 222 operating a suitable indicating dial 224. Signalling means for indicating whether the head is in its hoisted or lowered position are provided which consist of a double throw switch 226, normally spring biased downwardly and adapted to be moved upwardly by a stop 228 carried by the head I0. Switch 226 energized a light signal 230 when head I is up and a light signal 232 when the head I0 is down. The solenoids I6 and 16 may be controlled by suitable momentary contact push button switches 234 and 236.

For the purpose of permitting operation of the device in case of' failure of electric power, a hand vcrank .236 may be applied to the motor shaft for operating the pump I4 manually to raise and lower the head I0. The member I2 may be rotated under these conditions by the f of the motor cylinders falls, that the pipe 40 is no longer subject to high pressure and the piston 30 accordingly moves downwardly to bring the pump into full displacement position. As

soon as the piston 94 passes the conduit 40, the latter is again connectedto the discharge side of the pump and the pump regulates itself to maintain a constant delivery pressure. As the pistons 94 and 96 approach the end .of their stroke they are deceleratedby the cushioning hand crank I64 in which case a check valve 240 V bypasses oil from the line 64 to the line I48 when the motor is operated in either direction and acts to pump fluid into the line I52., In case of power failure the valve spool 14 may be operated'manually by the handle 242.

. In operation, starting with the parts in the position shown in the drawing and with the motor' driving the pump I4, it will be seen that so long as the valve 68 remains in its upper or hoisting position, fluid will be delivered by the pump I4 through the conduit 44, check valve 45, chamber 46, conduit 66, valve 68, conduit-64 and check valve I30 to the lower ends of cylinders 90 and 92. With the pistons 94 and 96 at the upper limit of their strokes, pressure will build up in cylinder 90 and being transmitted through conduit 40 to the annular chamber 36,

will move the piston 30 upwardly to approximately the position shown where the displacement of the pump is just suflicient to make up for the total leakage in the high pressure side of the system.

When it is desired to lower the head I0 and rotating member I2, the switch 234 may be depressed energizing solenoid I6 to shift the spool I4 downwardly, connecting conduit 66 with conduit 82 and connecting conduit 84 to tank. Under these conditions pressure oil passes through conduit 82 and through the cushioning check valves to the head ends of the cylinders 90 and 92. This pressure is exerted on the inner face of the latch plungers I06 and is sufllcient to overcome the springs I06, withdrawing the latches from engagement with the collars I02 and I04. Before the latches move outward, pressure is supplied from conduit 82 through check valve I34, conduit I32, valve I22 and conduits I28 and 84 to the lower ends of the motor cylinders. Due to the differential area of the pistons the net fluid force exerted thereon is in the upward direction, tending to relieve the gravity load on the latches I06 and thus making their outward movement free from frictional drag caused 'by the weight of the head I0 and associated parts.

As soon as all of the latches I06 have moved outwardly, pressure oil is transmitted through the series circuit at the latch valves through conduits IIO, II2, H4, H6 and II9 to the upper operating chamber I20 of the valve l22. The latter shifts downwardly discharging oii'from the lower chamber I24 through conduit I25 to the tank. With the valve I22 in its lower position, conduit I32 is cut oil from conduit I28 and the latter is connected to tank through conduit I36, restrictor I38, valve 68, conduit 12, chamber 52 chambers, pressure remaining on top'of the pistons to hold the head I0 in its downward position. With the pistons thus stalled at the bottom of the cylinders, the pump displacement regulator again swings the yoke 24 to approximately neutral position;

.As the head I0 reaches the bottom of its stroke,

arm I46 depresses plunger I44 of valve I42 thus connecting conduit I46 to the delivery conduit 44 of-the pump. The system is now ready for operation of the rotating element I2 under the control of the follow-up valve I50. Thus, if the handwheel 2| 6 be rotated to any new position this motion is transmitted through the Selsyn system 2I2--2I4 to the sleeve I60, which controls the input member of the follow-up valve I50. The relative displacement between the input member and the response member thus produced, opens the valve I50 to flow of oil from conduit I48 to whichever of the conduits I54 or I56 will cause rotation of the motor I58 in a corresponding direction. The discharge from the motor returns from the follow-up valve I50 through conduits I52 and 64 to the tank. The unit I2 may thus be rotated to any desired position, at will,

by operation of the handwheel 2I6. The hearing repeater 224 of course indicates all movements of-the member I2.

If the member I2 be rotated too far in a given direction, the limit stop arm I88 is caused to abut vthe pilot valve lever I90 an opens communication between port I94 and either port I96 or I98, depending upon the direction in which the arm I66 approaches the lever I90. Assume, for

' example, that the handwheel 2 I6 is turned in the direction causing the follow-up valve I50 to admit pressure oil to the conduit I54 and thus causing the shaft I10 to rotate in the direction of the arrow. The direction of rotation of the other shafts will be as indicated by the arrows, thus moving the lever I90 clockwise .and connecting port I94 to port I96. The control chamber 54 of the relief valve 50 is thus vented to tank through conduit 62, port I94, valve I92, port I96, conduit 204, check valve 208, follow-up valve I50 and conduits I52 and 64. Oil discharged by the pump is thus by-passed at the valve 50 from chamber 46 to chamber 52 and through conduit 64 to the tank, thus preventing further operationof the motor I56 in that direction.

If now the handwheel 2I6 be turned in the opposite direction so as'to move the follow-up valve to connect conduit I56 to the. pressure conduit I46, it will be seen that pressurev willbe immediately transmitted to theconduit 204.=and will back up against the check valve 206 thus preventing further venting of the oil from chamber'54 of the relief valve and permitting the latter to close. Thus motor I 58 may bebacked away from its limiting position.

Upon continued rotation to the other limit determined by the arm I88, the operation is similar to that described except that all shafts turned in the direction opposite to the arrows and the relief valve is vented through conduit 206, instead of conduit 204. Here again, as soon as the follow-up valve operates to back up from the limiting position, pressure builds up behind the check valve 2I0 and the relief valve is no longer vented.

When it is desired to raise the head I2, switch 236 is closed, energizing solenoid I8 and lifting the valve spool I4 again to the position shown in the drawing. The rod ends of the cylinders 90 and 92 are now connected to tank through conduit 82, conduits 10, I2 and 64. Pressure oil from the chamber 46 is admitted to the conduit I25 and chamber I24 to shift the valve I22 upwardly, discharging oil from the chamber I20 through conduit II8, the three-way valve at the right hand latch plunger I06 and the drain conduit 209 to tank. It will be noted that due to the tank pressure existing in the upper ends of cylinders 80 and 92, that the springs I08 move all the latch plungers I06 inwardly. Pressure oil is also delivered from the conduit 86 through conduit 84 and check valve I30 to the lower ends of the cylinders 80 and 92, thus moving the pistons and the head I upwardly until the position, shown in the drawing, is reached. The latch plungers I06 then engage the collars I02 and I04 and since the piston 94 is now above the conduit 40, the pump 24 is again regulated to its small displacement position suflicient to maintain the desired pressure beneath the pistons 94 and 96.

If for any reason the supply of electric power should be interrupted, the pump I4 may be operated by the hand crank 238 to lower the head I0 in a similar manner to that previously described. The valve spool 14 may be operated manually by the handle 242 for this purpose. When the head I0 has descended check valve 45 prevents upward movement thereof, this valve also serving to prevent falling of the head I0 while it is being hoisted by the operation of the hand crank 238. When the head is in its lowered position the same may be rotated manually by the operation of the handwheel I64 which, by means of the stop mechanism I68, provides a direct mechanical drive to the rotatable member I2. The motor I58 is, of course, mechanically driven during such operation and oil discharged into the tank conduit I52 may return to the opposite side of the motor I58, through conduit 64 and check valve 240. The flow is always in the same direction regardless of the direction of operation of hand wheel I64 since the follow-up valve I50 reverses connections to the motor I58 each'time the hand wheel is reversed.

What is claimed is as follows:

1. In a fluid power transmission system the combination with means forming a source of fluid under pressure, of a reciprocating fluid motor operable on fluid supplied from said source, a translatable load device continuously biasing the motor in one direction, latch means for releasably retaining the load device in retracted position against the bias, means for releasing the latch means, valve means for selectively controlling the supply of fluid to cause the motor and load device to move in one direclatch means for causing admission of fluid to the motor in a direction overcoming said bias when the valve means is operated to initiate motor travel in the opposite direction and effective to reverse the motor when the latch means is released.

2. In a fluid power transmission system the combination with means forming a source of fluid under pressure, of a reciprocating fluid motor operable on fluid supplied from said source, a translatable load device continuously biasing the motor in one direction, a plurality of separate latch means for releasably retaining the load device in retracted position against the bias, means for releasing the latch means, valve means for selectively controlling the supply of fluid to cause the motor and load device to move in one direction or the other, and means controlled by the latch means for causing admission of fluid to the motor in a direction overcoming said bias when the valve means is operated to initiate motor travel in the opposite direction and effective to reverse the motor when all the latch means are released.

3. In a fluid power transmission system the combination with means forming a source of fluid under pressure, of a reciprocating fluid motor operable on fluid supplied from said source, a translatable load device continuously biasing the motor in one direction, latch means for releasably retaining the load device in retracted position against the bias, means for releasing the latch means, valve means for se lectively controlling the supply of fluid to cause the motor and load device to move in one direction or the other, a valve in circuit therewith for also controlling the supply of fluid to the motor, and means for operating the last named valve to cause admission of fluid to the motor in a direction overcoming said bias when the first valve means is operated to initiate motor travel in the opposite direction and effective to reverse the motor when all the latch means are released.

4. In a fluid power transmission system the combination with means forming a source of fluid under pressure, of a reciprocating fluid motor operable on fluid supplied from said source, a translatable load device operably connected to said motor, latch means for restraining the load device against motion in one direction, valve means for releasing the latch means when the fluid to the motor to cause the motor and load device to move in one direction or the other, means for erleasing the latch means when the valve means is operated to cause movement of the motor in said one direction, and means effective while the latch means is effective for relieving load on the latch means when the valve means is thus operated.

5. In a fluid power transmission.system the combination with means forming a source of fluid under pressure, of a differential piston and cylinder motor, valve means for selectively connecting the large end of the cylinder to said source or to exhaust fluid therefrom, latch means for releasably restraining the motor against motion in the direction to exhaust fluid from the large end of the cylinder, means for releasing the latch means, and means controlled by the latch means for maintaining pressure fluid in the large end of the cylinder when the valve means is operated to exhaust fluid therefrom, the last means being rendered inefiective by release of the latch means.

6. In a fluid power transmission system the' a'translatable load device continuously biasing the motor in one direction, a plurality of separate latch means for releasably retaining the load device in retracted position against the bias, valve means for selectively controlling'the supply of fluid to cause the motor and load device to move in one directionor the other, hydraulically actuable means for releasing the latch means upon movement of said valve means to supply fluid to move said load in the direction of the bias, auxiliary valve means for directing fluid to the motor in a direction overcoming said bias when the valve means is operated to,

initiate motor travel in the opposite direction and operable to reverse the motor, and means in hydraulic series with each of said latch means and operable when all latch means are released to reverse the motor by shifting said auxiliary valve.

7. In a fluid power transmission" system, the combination with means forming'a 'source offluid under pressure, of a differential piston and cylinder motor, a fluid line connected .to the large end of said' cylinder, a fluid line connected to the small end, valve means for directing fluid from said source to one or the other of said lines, load means biasing said motor against the large end, latch means for releasably restraining mentarily connect said lines to admit pressure to both ends of said motor when saidvalve means is shifted to direct fluid to the small end of said motor thereby causing a momentary movement of said load against said bias, said last means being rendered ineifective by release oi! the latch means.

8. In a fluid power transmission system, the combination with means forming a source of fluid under pressure of a difierential piston and cylinder motor, a fluid line connected to the large end of said cylinder, a fluid line connected to the small end, valve means for selectively controlling the supply of fluid to cause the motor to move in one direction or the other, load means biasing said motor against the large end, a plurality of separate latch means for releasably restraining the motor against said load device. hydraulically actuable means for releasing the latch means upon movement of said valve means to supply fluid to the small end of said'motor,

means connected in series with said latch means,

and the small end of said motor arranged to momentarily connect said lines 'toadmit pressure to both ends of said motor when said valve means is shifted to direct fluid to the small end, said the motor against said load bias, and means operably connected with said latch means to molast named means being shiftable by pressure from said small end when all of said latch 4 means are released to cut cit the connection between said lines and to connect the large end to exhaust.

HARRY F. VICKERS. 

